1. Field of the Invention
The invention relates to a method for deciding on the acceptance or non-acceptance of a call, to a circuit module, to a communication terminal, to a portable unit, in particular a chip card, and to a network component for a telecommunication network.
2. Description of the Related Art
The opportunities for being able to reach a certain subscriber at almost any time and at almost any location are increasing rapidly. Contributing hereto is primarily a denser telephone network with sometimes several terminals connected in parallel and being capable of accepting a call with equal access privilege, for example inside a single-family home or in an office, warehouse or shop. Included herein are also the different types of call rerouting, including call forwarding. Furthermore, the non-wire-line terminals, like cordless phones, mobile radio, mobile phones and communication via satellite, increase accessibility. An added feature is provided by the use of uniform subscriber numbers, obviating the need to distinguish between the terminal in the office, in the car and at home. The certain substitute can also initiate a call home or to a central office from a foreign terminal and to treat this terminal, by appropriate signaling, temporarily as the certain subscriber's own terminal. For such calls and signaling, there are provided, for example, chip cards or telephone cards which, on one hand, allow rerouting of incoming calls to this terminal and, on the other hand, charge the tolls for outgoing calls to the certain subscriber own account. Although specially designed terminals are presently required for this purpose, this can also be accomplished by acoustic or inductive coupling.
Consequently, an appropriate defense against misuse is required.
The easiest defense is muting or ignoring the telephone terminal. By providing a telephone number filter, only certain callers would be connected and announced by a different ringing.
It is rather common to connect a telephone answering machine in parallel, for the certain subscriber to listen in when the caller speaks, and to decide only then if the certain subscriber prefers to accept the call or not. Aside from the fact that this is rather annoying provided the certain subscriber hears the call at all, this method is not adapted to, for example, rouse a sleeping tenant in a burning house.
To this end, a ranking of calls or callers according to urgency could help. According to the solution described in U.S. Pat. No. 5,329,578, a high priority could, for example, be assigned to the police and the fire departments. Aside from the fact that these departments would then have to use the known emergency numbers also for outgoing calls, the rerouting of calls in this and other situations will here not make sense.
One may approve that the boss may be entitled to cut into every official meeting with his call, and that the grandmother may be entitled to interrupt a Christmas party in a remote mountain hut with her call. Conversely, this does not have to occur, as is provided in the U.S. Pat. No. 5,329,578 referenced above. And it is also doubtful if these two parties would like this to happen. This is particularly true in view of the higher cost associated with rerouting a call in public networks.